Mechanical sweepers are well know in the arts. Typically, these sweepers employ one or more vertical axis brushes which extend outwardly from the sweeper. Dirt is swept up by the brushes into a scoop which deposits the dirt and debris in a dirt receptacle. One type of sweeper, disclosed in U.S. Pat. No. 3,937,174, now expired, uses a pair of vertical axis brushes driven by a worm gear arrangement. This arrangement allows the brushes to sweep debris into a dirt receptacle during a forward stroke. On the reverse stroke, the worm gear wheel pivots around a drive shaft such that rearward movement of the sweeper also causes dirt and debris to be swept into a dirt receptacle during the reverse stroke.
Because such devices can be used both outdoors and indoors, the sweeper may encounter a variety of surface types. Therefore, it is desirable to adjust the force that the brushes apply to the surface being cleaned. For example, on rough surfaces, it is desirable to engage the brushes with less force to reduce pushing effort, whereas on smooth surfaces it is desirable to engage the surface with more force to get better debris pickup. Prior designs have addressed this problem by adjusting the height of the wheels that drive the sweeper brushes. A drawback to these designs is that the brushes are located on the front of the sweeper and the operator is positioned behind the sweeper. Thus, the operator must-move around the sweeper to make an adjustment for different surface types.
In addition, these cleaners typically include a dirt receptacle for transporting recovered dirt to a trash container. In some cleaners, the dirt receptacle includes the rear wheel of the cleaner. A drawback to this design is that removal of the receptacle prevents movement of the remainder of the sweeper. In addition, such receptacles are difficult to re-align with the sweeping portion of the sweeper after the dirt receptacle has been emptied.
What is needed therefore, is a mechanical sweeper configuration that overcomes the above-mentioned drawbacks.